When the spectators flee from the arena, one ticket booth is knocked over, leaving the open side facing up. In later shots a closed side faces up, and still later this same booth disappears completely.
Early on, young Lope tells Tuck Kirby that the arena is two miles outside of the town. This is confirmed by Tuck encountering Professor Bromley's paleontological digs in open desert during his return from his first visit to it. However, at the film's climax the arena is clearly within the town.
In the end chaos a number of people run into a church (pursued by the dinosaur). Some men outside try to open another set of very large church doors to let everyone back out to escape (or to assist in fighting the dinosaur once inside themselves). They are unable to open the doors, but keep trying to. In the utter chaos they surely cannot know how many people ran inside via another entrance, and the doors they are pulling are opaque. When the people trapped inside free themselves and emerge through the doors however (which were locked from the inside and that explains the difficulty the men outside had), the men outside see them come out, and immediately retire without looking inside and cease trying to help or get in, even though no words are exchanged. How did the men outside know the few people who emerged were the entire trapped contingent? For all they know there could still be people inside with the dinosaur.